Improvement in atmospheric hammers



" 3Sheets-SheetI.

J. C'. BUTT'ERFIELD.

ATMOSPHERIC HAMMER.

' No. 176,400. Patented April 18, 1875,

Fig. J

-Wi;messes lm/eubor- -l N-PETBS, FNOTOVUTHOGRAPHER, WASHINGTON, I}v C-3Sheets-Sheet2. J. C. BUTTERFIELD.

ATMOSPHERIC HAMMER. v No. 176,400. Patented April 18, 1876.

Wfiuesses lm/e'mio'r Za /2W 3$heets -Sheet3. I. C. BUTTERFIELD.

ATMOSPHERIC HAMMER. Patented Apr'1l18,1876.

-W"Lmesseslm/encor 0 I j I W I flaw w UNTTED' STATES PATENT @FFIC'E-JOHN C. BUTTERFIELD, OF CHICAGO, ILLINOIS,

IMPROVEMENT IN ATMOSPHERIC HAMIV IERS.

Specification forming part of Letters Patent No. 176,400, dated April18, 1876; application filed 5 April 6, 1876.

T0 allwhom it may concern Be it known that I, J OHN C. BUTTERFIELD, ofthe city of Chicago, county of Cook and State of Illinois, have inventeda new and useful I mprovement in Atmospheric Hammers, which is fully setforth in the following specification.

Atmospheric hammers have heretofore been constructed, and theircharacteristics may be classed as follows: on, atmospheric pressureadded to the weight of the hammer to increase the impact; b, expansionof compressed air to increase the impact a, compression above and belowthe piston, the former to elevate the hammer, and the latter to increasethe impact. a and 0 also propose to regulate the force of the blow byair cushioning; a and b elevate the hammer by mechanism; celevates bycompressed air.

For the purpose of clearly explaining my invention, 1 will point out thematerial differences between it and atmospheric hammers heretofore made.r

A principal desideratum in hammers of this class is to intercept theshock of the hammerblow, so that it shall not be transmitted to theframe of the machine. In the hammer c, alluded to above, this isaccomplished by the interposition of a body of air between the hammerand its motive mechanism, but shock is nevertheless transmitted throughthe close packings required to prevent the escape of air under pressure.In my machine the transmission of shock is prevented by theinterposition of cushions of an elastic solid, like indiarubber.

The hammers alluded to have their air-cylinders in line with the hammer,and the power required is suificient to lift said hammer as dead weight.My hammer is counterbalanced, and therefore moved with a minimum expenseof power.

The hammers alluded to propose only to cushion in one direction, and canonly control the force of the blow with variations of the rapidity ofdelivery. My hammer cushions in either or both directions, and the forceof the blow can be controlled perfectly irrespective of the rapidity ofdelivery.

From-the above it will be perceived that I do not employ air-springs forthe purpose of intercepting shock, but solely for the purpose ofoperating and controlling the action of the hammer, as will more fullyappear in the following description.

My invention, therefore, consists, first, in a balanced atmospheric orair spring hammer second, in a supplemental air-cylinder, capable ofcushioning in either or both directions and to any desired extent; andalso, third, in tightenertreadle and brake; and, fourth, in thecast-metal hammer-beam.

The leading elements of my invention are a hammer, A, moving in uprightguides, a horizontal oscillating hammer-beam, B, mount: ed on journalsabout midway otits length, an air-cylinder, 0, attached to said beam, atthe end opposite the hammer, and a piston, D, in said cylinder, operatedby the crank or eccentrio rod E. The intercepting cushions F form thesubject of Letters Patent No. 156,276, granted to me October 27 1874.The frame G supports all of the working parts of this hammer, andwithout intending to limit myself to the exact details of constructionand arrangement, but for convenience only, I will describe the machineas it is shown in the accompanying drawings, wherein- Figure 1 is a sideelevation. Fig. 2 is a sectional elevation of the principalair-cylinder; Fig. 3 is a sectional elevation of the supplementalair-cylinder. Fig. 4 is a side elevation of the treadle and tightener.Fig. 5 is a front elevation of the tightner. Figs. 6, 7, 8, and 9, aredetails of the eccentrics. Fig. 10 is a side elevation of thehammer-beam. Fig. 11 is a plan of the same. Figs. 12 and 13 are frontand edge elevations of the hammer and hammer-rod. i

1. The frame G has at its top the boxes 9 g, one on either side for thereception of the journals b b of the hammer-beam B. The guideframe a andanvil-block c are upon the front side of said frame, and two arms, at d,project from the rear side near the base to support the boxes in whichthe crank-shaft Hrevolves.

The hammer rod or piston e is joined to; the; front end of the beamB'bya wrist-pin, f,

which is driven transversely through the end of said beam. At the rearend the hammer and transverse to the beam whereon the oscillatingcylinder 0 is suspended. The piston D works in the cylinder U, and itspiston-rod E is coupled to the crank or eccentric rod, which is actuatedby the eccentrics J. The cylinder 0 is closed at each end, and has avent-hole, k, in its side about midway of its length. Power istransmitted to the pulley K on the shaft- H by means of a belt, in theusual manner. It will be perceived that I have a hori-- zontaloscillating hammer-beam, with fulcrum about midway of its length, andfrom the front end of this beam the hammer B is suspended, and thecylinder 0 is attached to its rear ends. This cylinder and itsattachments are .constructed to equal in weight the hammer B and itsattachments, so that said hammer and its working-connection's arebalanced upon the hammer-beam journals 1), and to move said hammerrequires only sufficient power to overcome the inertia and friction ofthe parts, whereas with all atmospheric hammers heretofore, the requiredpower must be sufficient not only to overcome inertia and friction, butto raise the dead weight of the hammer in addition. These hammers,therefore, require a maximum power, while mine requires only the theminimum. WVhen the 'piston D descends, the compression of the air in thebottom of the cylinder 0 begins as soon as said piston passes the vent7c, and said cylinder will begin to descend and the hammer will begin torise as soon as the compression is sufficient to overcome the inertiaand friction of the moving parts. Then the movement'of the piston isreversed, expansion of the compressed air and momentum will'cause "aslight continuance of the upward motion of the hammer, but this will bequickly checked by compression of air in the top of the cylinder 0 asthe piston D moves upward, and the hammer will thereby be drivendownward upon the anvil, the intensity of the impact being proportionateto the rapidity of the reciprocation of the piston.

As the eccentric or crank passes its lower center, the weight of thepiston D, with its rod E and attachments, is sustained by the compressedair in the-bottom of the cylinder 0, and therefore the eccentric isentirely relieved of thrust in reversing the motion of said piston androd. The same effect in a reverse direction takes place'as the eccentricpasses its upper center.

The above-described operation is effective, but is subject to a singledisadvantage, viz: an upward thrust upon the bearings b, occasioned bythe continued upward movement of the hammer, as above mentioned, andthis effect is counteracted by the second part of my invention, (2d,)which relates to a supplemental air-cylinder, L, the piston-rod i ofwhich is jointed to the hammer-beam B, by the center screws m in frontof the fulcrum b. The cylinder L is mounted upon center screws 12, so

that it is capable of the required oscillation as the beam B moves uponits fulcrum. The

cylinder L is smaller in caliber than the cyl-, inder 0. As its pistonis moved from end to end in the cylinder L, its eflectis in oppositionto said cylinder 0, as follows: When the cylinder O descends under theforce of the compressed air in the bottom of said cylinder, the piston lis drawn to the top of the cylinder L, and the tension of the compressedair therein is opposed to the downward movement of the said cylinder 0but this effect may be graduated so as to equal only the power necessaryto overcome the upward thrust of the hammer, and then, by the expansionor reaction of the aircompressed in the top of the cylinder L, to impartto the hammer its initial downward movement. 7

By the proper graduation of these opposing forces, all upward thrust ofthe journals b against the caps of the boxes gmay be prevented, and theoperation of the hammerbeam will lie-unaccompanied by jar or shock.

The required control of the resistance in the cylinder L is obtained bymeans of the valves p, which enables the attendant to regulate theamount of air cushioning by adjusting said valve to permit a greater orless escape of the compressed air. The piston D passes thevent k atmid-stroke; but it is necessary that the piston P in the cylinder Lshall cut off its vent q almost as soon as the-movement of said pistoncommences. Therefore it'is possible to secure about double thecompressionin cylinder L as compared with cylinder 0, and acorresponding ease and delicacy of adjustment at the valve 19. 1therefore make said piston P very long, nearly equal to half the lengthof said cylinder L, and provide two vents, q, so that air may enter bothtop and bottom ends of said cylinder.

In atmospheric hammers heretofore the force of the blow could only becontrolled by regulating the speed of the hammer, and it is ofconsiderable importance to control the blow without varying the speed.This is readily effected by means of a valve, 7', at the bottom of thecylinder L. When this valve is closed the air compressed under thepiston P takes up the force of the hammer-stroke downward, and withoutin any degree affecting the speed, and this effect may he graduated atwill by adjusting said valve 1' to permit an escape of a greater or lessportion of the confined'air.

3. The machine is provided with the usual treadle S and tightener T,whereby the speed may be regulated in the common manner. The treadleconnection, however, is peculiar. The .treadle S has its fulcrum uponpins 8 driven into the sides of the frame G near its base, and extendsto the rear of said fulcrum-pins. On one side it is provided with acounterweight, and on the other it is provided with a segment-rack, t,which meshes with a similar segment-rack, u, on the front end of thetightener-arm U, whiehisjournaled at its rear ends upon a pin,'v, driveninto the extremityof the arm d on the same side of the frame with thepulley K. A projecting shoeyw, on the side of the tightener-arm U enterswithin the rim of the pulley K, and acts as a brake thereon, when thetightener falls down out of action, to stop the motion of thedriving-shaft H.

4. The hammer-beam B requires sutfi'cient strength and stiffness to movethe hammer with the requisite speed, and at the same time it isdesirable to reduce its weight as much as may be compatible with therequisite rigidity.

I have therefore devised a cast metal trussed beam, which, upon trial,has been found to answer excellently.

Said beam B consists of a web, a, with top and bottom flanges y, andangular ribs or trusses 2 extending from end to end, as shown.

The web m is in the center longitudinally, and the flanges 3 and ribs zare arranged on each side of said web.

This beam is cast in a single piece.

Having described my invention, what I claim as new is-- 1. A hammer, A,attached to one end of a hammer-beam mounted on journals about midway ofits length, combined with an aircylinder, 0, attached to the oppositeend of said beam, and a piston, D, in said cylinder, actuated by aneccentric or crank rod, E, operating in the manner and for the purposeset forth. Y 7

2. An oscillating hammer-beam, B, mounted upon journals about midway ofits length, and attached to opposite ends of the same, a hammer, A, andan air'cylinder, C, the piston whereof is actuated by acrank oreccentric, combined with a supplemental cylinder, L, with an adjustablevalve, 10, near its upper end, and its piston-rod joined to said beambetween its fulcrum and the hammer, for the purpose of arresting theupward thrust of said hammer, as set forth.

3. An oscillating hammer-beam, B, mounted upon journals about midway'ofits length, and attached to opposite ends of the same,ahammer, A, and anair-cylinder, O, the piston whereof is actuated by a crank or eccentriccombined with a supplemental air-cylinder, L, provided with anadjustable valve, 1', near its lower end for the purpose of cushioningthe downward blow of the hammer to regulate the impact thereof withoutaffecting the speed of delivery.

4. The air-cylinder L provided with adjustable valves 12 and 1' near itsupper and lower ends respectively, and with a piston, P, in lengthnearly equal to the length of stroke, combined with a hammer, A, and itsoperative mechanism.

5. The treadle S, provided with the rack 6, combined with thetightener-arm U, provided with the rack u, for the purpose of operatingsaid tightener, as set forth.

6. The combination of the tightener-arm U, substantially as described,and the laterallyprojecting shoe 10 adapted to enter within the rim ofthe pulley K, and act as a break thereon? x 7. A hammer-beam forpower-hammers, constructed of cast metal with a central longitudinalweb, x, flanges 3 and angular truss ribs 2, as set forth.

J. c. BUTTERFIELD. Witnesses r R. D. 0. SMITH, 0. CLARENCE PooLE.

